Scientists at Kaunas University of Technology (KTU) have uncovered a promising circular-economy breakthrough: textile waste ash can replace part of Portland cement while improving concrete strength, according to new research published in Construction and Building Materials.
The study tackles two major sustainability pressures:
1. Soaring textile waste volumes, much of which ends up in landfills or incinerators, and
2. The carbon-intensive production of cement, where clinker generation accounts for ~90% of emissions.
By applying controlled thermal treatment, KTU researchers produced an ash with the desired chemical profile and fineness, making it suitable for use as a supplementary cementitious material (SCM).
Replacing up to 7.5% of cement with textile ash produced concrete mixes up to 16% stronger than conventional formulations. The researchers attribute this to improved particle packing and enhanced pozzolanic activity — a reaction similar to what gives fly ash and calcined clay their performance benefits.
The team also tested recycled polyester fibres derived from discarded clothing. At doses of around 1.5%, the fibres:
• Increased compressive strength by 15–20%
• Improved freeze–thaw resistance
• Reduced microcracking
Used together, textile ash and fibres provide both chemical and mechanical reinforcement to the cement matrix. If scaled, textile waste could become a locally available, lower-carbon SCM — reducing clinker use, cutting waste-incineration emissions, and lowering material costs. Regional production models could use locally sourced waste streams, supporting circular-economy objectives across Europe and beyond.
